Abstract:
The relationship between sediment texture, micro-organisms (diatom and Foraminifera), water column currents and water depth was investigated along the shoreline (to the 100m contour) of the Victoria Land coast. Seafloor sediment samples were taken from shore normal transects at seven sites on the southwestern Ross Sea coast (Explorers Cove, Cape Bernacchi, Cape Roberts, Tripp Island, Gergory ... Island, Dunlop Island and Blue Glacier) and from Cape Armitage, Ross Island. The transects represent a range of coastal types (exposed to embayed) with a variety of substrates including bedrock, gravel, sand, mud and sponge mat. At each site, a bathymetry survey was carried out to determine slope and topography of the sea floor, transects of the sea floor were sampled for sediment and biota to 100 m water depth and the ocean current was measured at each site. Samples were photographed, described and split for preserving an archive specimen and for foraminiferal work and grain size analysis. Water samples for oxygen and carbon isotope analysis were taken at the 100m site of each transect. Samples were collected at 10m below the sea ice and 5m above the sea floor. pH was measured within 2 hours of collection. This area is interesting because previous drill cores show how variations in species diversity and sediment texture may be used to follow sea level changes in cored sequences when compared with the modern shoreline.